The use of dual—Doppler radar data in the study of 1998 meiyu frontal precipitation in huaihe river basin

<p>Using 5 years of operational Doppler radar, cloud-to-ground lightning observations and NECP reanalysis data, this study, for the first time for such a purpose, examines the spatial and temporal characteristics of and correlations between summer storm and lightning over the Yangtze-Huaihe River Basin (YHRB), with a special emphasize on their diurnal cycles. The sub-seasonal variability of the lifetime, storm top, max reflectivity and cell-based vertical integrated liquid (VIL) water of storms are also investigated using the Storm Cell Identification and Tracking algorithm. Results show that storms over YHRB occur most frequently during the Meiyu period. Storms are largely associated with Meiyu fronts during the period and show a fast-moving speed and moderate intensity (proxies including storms top, max reflectivity and VIL). The diurnal variations of storms embedded in Meiyu front are weak. The storm intensity becomes much stronger in the post-Meiyu period due to the increased atmospheric instability. Higher occurrence frequency of CG lighting can also be found during the post-Meiyu period. The diurnal cycles of storm and CG lightning in the post-Meiyu period show a unimodal pattern with an afternoon peak corresponding to solar heating effect. An inverse correlation between the lightning numbers and the mean value of peak current (MPC) for the negative CG lightning is found during the pre-Meiyu and Meiyu periods. The diurnal variation of MPC for the negative CG lightning agrees well with the storm intensity to some extent.</p>

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Statistical Objective Analysis of Dual-Doppler Radar Data from a Tornadic Storm

Journal of Applied Meteorology ◽

10.1175/1520-0450(1976)015<0059:soaodd>2.0.co;2 ◽

1976 ◽

Vol 15 (1) ◽

pp. 59-68 ◽

Cited By ~ 4

Author(s):

Gerald M. Heymsfield

Keyword(s):

Doppler Radar ◽

Radar Data ◽

Objective Analysis ◽

Doppler Radar Data ◽

Dual Doppler Radar

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Shear Instability Wave along a Snowband: Instability Structure, Evolution, and Energetics Derived from Dual-Doppler Radar Data

Journal of the Atmospheric Sciences ◽

10.1175/jas-3392.1 ◽

2005 ◽

Vol 62 (2) ◽

pp. 351-370 ◽

Cited By ~ 17

Author(s):

Masayuki Kawashima ◽

Yasushi Fujiyoshi

Keyword(s):

Linear Growth ◽

Doppler Radar ◽

Growth Period ◽

Radar Data ◽

Shear Instability ◽

Instability Wave ◽

Horizontal Shear ◽

Pressure Work ◽

Doppler Radar Data ◽

Dual Doppler Radar

Abstract This article presents a detailed analysis of a meso-γ-scale (∼17 km wavelength) shear instability wave along a snowband using a series of dual-Doppler radar data. The wave developed along a low-level shear line that formed under the strain wind field caused by an adjacent mesoscale vortex. The horizontal wind shear across the line was largest at lower levels, and the eddy-component horizontal winds and the retrieved pressure anomaly showed a bottom-intensified structure as well. The resultant vertical pressure gradient force was found to be responsible for the enhancement of alternating updrafts and downdrafts that were subsequently related to the formation of the reflectivity core/gap structure of the wave. Eddy kinetic energy (EKE) budgets of the evolving disturbance were investigated using time series of retrieved kinematic and thermodynamic data. The wave grew at an approximately constant growth rate for about 40 min from its onset. The EKE in this quasi-linear growth period was primarily generated by the horizontal shear that decreased with height. The pressure work was found to remove about two-thirds of this generation in the layer below 1 km, while in the upper layer it was constructive to EKE generation and comparable to the generation of EKE by horizontal shear. These results indicate that the source of EKE was basically located at low levels and the energy was transported upward mainly by the pressure work. After the quasi-linear growth period, horizontal shear generation rapidly decreased and EKE peaked. The buoyancy generation of EKE was small but positive in the quasi-linear growth period, then became negative because of the development of thermally indirect circulations.

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